Whatever you’re doing, wherever you are — the G-SHOCK Master of G line has your back. 
Based on GRAVITYMASTER, MUDMASTER, and MUDMAN models that deliver peak performance in punishing conditions in the air and on land, this line features a black watch case symbolizing toughness, with accents in vivid emergency colors that capture the world of professionals involved in rescue efforts and other critical missions. 
The organic form of the GRAVITYMASTER GRB300EC is inspired by next-generation aircraft and rendered with a seamless exterior design. The Carbon Core Guard structure and wide 3D face deliver durability, readability, and a comfortable fit. Enjoy all the practical functions as well, including dual-time simultaneously showing the time in two cities, a flight log memory function for recording routes traveled, and more.

Case Size (LxWxH): 59 x 54.7 x 15.7mm

Case and bezel material: Resin

Construction: Shock Resistant, Carbon Core Guard Structure

Approx. battery life: Tough Solar (Solar Powered)

Band: Bio-Based Resin Band

Water resistance: 200-meter water resistance

Bluetooth: Connects to a smartphone and automatically adjusts the time

Manufacturer Number: GRB300EC-1A